Complications of Fracture Healing

Nonunion of the fragments of the dental bone is an occasional complication of the dental healing process as examined under dental surgical microscopes. This results when calluses of osteogenic tissue overreach. The two fragments fail to meet and fuse or when endosteal formation of the dental bone is inadequate. The causes of nonunion are not always clear, although in general it may be said that anything which delays growth and fusion of the collars is a factor. Nonunion is relatively common in elderly person, in whom it is apparently related to a lack of osteogenic potential of cells.

Fibrous union in fractures is another complication of healing which arises usually as a result of lack of immobilization of the damaged bone. The fractured ends or fragments are united by fibrous tissue, but there is failure of ossification. In certain circumstances this may produce pseudoarthrosis. Lack of calcification of newly formed bone in the callus may occur, but only in unusual circumstances of the dietary deficiency or mineral imbalance, which is seldom seen clinically. This may be produced in the experimental animal and observed through dental surgical microscopes.

The elimination of the periodontal pocket by gingivectomy has become a routine dental clinical procedure principally because of the excellent result which is generally attained. Numerous dental surgical techniques are in use for the removal of the dental tissue, and different types of postoperative dental packing materials are applied to control bleeding, maintain tissue position, relieve pain and keep the fresh dental wounds free of debris. Despite these variations, the general features of the healing process are still similar and must be understood before attempting to carry out such dental surgical procedure.

Early Healing Phase

Early healing phase of gingivectomy wounds take place rapidly regardless whether a postoperative pack is used. There is some evidence, however, that dental healing may be slightly facilitated by the dressing. Two days after the gingivectomy, the surface of the dental tissue is covered by a grayish blood clot. Beneath this clot, when examined under a dental surgical microscope, there is histologic evidence of delicate connective tissue proliferation. Even at this early stage there is also considerable activity of the dental epithelial cells bordering the dental wound preparatory to beginning of actual epithelialization. Four days after the operation, the deeper portion of the dental blood clot demonstrates considerable organization, while the more superficial portion exhibits dense numbers of pollymorphoneuclear leucocytes and trapped in the fibrinous measure. There is proliferation of young capillaries and young connective tissue cells into the base of the blood clot when the dental tissue is examined under dental surgical microscopes. Infiltration of polymorphonuclear leucocytes in the deeper connective tissue is present in varying degrees. The dental epithelium has extended over a portion of the wound below the necrotic surface layer of the clot, but above the proliferation and organizing connective tissue.

Late Healing Phase

Continuation of the dental healing process is manifested by a condensation of the young dental connective tissue with nearly complete organization of the clot after to eight to ten days. Clinically, at this period, the dental wound has a red, granular appearance and bleeds readily. Epithelization is usually complete with in ten to fourteen days after gingivectomy. The dental epithelium remains thin, however, and begins to mature and form pegs only after the two weeks interval. At this time, the inflammatory cells of the gum have largely disappeared, except for those in the subepithelial zone.

Healing of the interproximal dental tissue appears to lag behind that adjacent to the labial or buccal surfaces. This maybe partly because of the dental epithelium, which covers the interproximal tissue, must grow in from the labial and lingual areas, a relatively great distance.

The surface dental epithelium grows downward along the surface of the cementum with in a month after gingivectomy. This is a rather shallow proliferation which is in close physical apposition to the tooth.

Healing of the gingivectomy wound is basically similar to the healing of wounds elsewhere in the body, but is somewhat modified by the special anatomy of the involved regions. The chronic inflammation present in the disease does not adversely affect the healing process and actually may provide some stimulus for healing.

There are different factors that affect wound healing in the oral cavity.

Wound healing is an intricate process in which a selection of cellular and matrix components act together to restore the integrity of the injured dental tissue.

Location of the Dental Wound

The location of the dental wound is important in the fast healing of the dental wound. It is faster to heal a dental wound in which there is a good vascular bed than dental wounds in an area which is moderately avascular as observed in dental surgical microscopes.

Immobilization of the dental wound is important in dental wound healing. If the area of the dental wound is always in movement the formation of the new dental connective tissue, it is always interrupted in tissue reparative. For example, if the dental wound is in the corner of the mouth, delayed healing of the dental wound will occur. This is also important in the healing of dental bone fractures because if there is continuous mobilization there is also a delay or hindrance of healing.

Physical Factors

Too much trauma or injury to the dental tissue is clearly a prevention of a rapid bone healing. But in some instances, mild traumatic injury may actually help the healing process. For example, second wounds imposed in the site of the healing initial dental wounds heal more rapidly than the initial or single dental wound. In addition, the local temperature in the area of the dental wound influences the speed of healing, probably through the effect on local circulation and cell multiplication. Thus, in the environmental hyperthermia, wound healing is accelerated when the tissue is examined under dental surgical microscopes, while in hyperthermia healing is delayed.

X-ray radiation on wound healing has still been studied, through the use of dental surgical microscopes, if there is an effect in wound healing. But the low doses of radiation have a tendency to stimulate healing, while large focal doses of radiation tend to hinder healing.

Circulatory Factors

One of the circulatory factors that affect the delay of dental wound healing is anemia, although not all studies have confirmed this observation. Dehydration has been found also to affect the wound healing when sample dental tissues were examined under dental surgical mictoscopes.

Nutritional Factors

The person who is deficient in any vast variety of food has an effect on dental wound healing. These are the following:

1. Protein - It is one of the most important substances to be present in food to speed up wound healing, a primary component of numerous body tissues and a main component of a muscle tissue. Patients who lack protein or has a low intake of protein may have a protein deficiency which is called hypoproteinemia. In hypoproteinemia there is delayed appearance of new fibroblasts as well as a decreased rate of multiplication of fibroblast in wounds. Foods which are high in protein are nuts, cherries, egg, meat, bananas, apricot, beans and grapes.

2. Vitamins - The most nutritional vitamins that speed up wound healing is vitamin C or ascorbic acid. It helps manufacture norepinephrine, a neurotransmitter that carries messages along the nervous system. The substance that builds blood vessels, bone, tendons, ligaments and cartilage is the collagen which needs Vitamin C or ascorbic acid to manufacture collagen formation and formation of normal intercellular substance of the connective tissue.

There have been no known wide studies of possible effect of dental wound healing in vitamin A and vitamin D, but there are reports that vitamin A slows down healing and that vitamin A and D, as in cod liver oil, promotes dental tissue repair.

There have been studies in relations in vitamin D in which riboflavin and pyridoxine deficiencies result in delayed dental would healing process.

Age of Patient

It has a big relation that an age of patient plays a factor in wound healing, persons who are younger heals wound rapidly compare to the elderly, and the rate of healing appears to be in verse proportion to the age of the patient. The cause of this is unknown, but probably relates to the general reduction in the rate of the tissue metabolism as the person ages, which itself may be manifestation be of decreased circulatory deficiency.

Infection

Dental wounds which are entirely protected from bacterial irritation heal slowly than dental wounds which are exposed bacteria or other mild physical irritation. It is clear that severe bacterial infection slows the healing of dental wounds.

Two Types of Healing

Primary Healing.

Primary healing or healing by first intention is a type of healing which occurs after the excision of a piece of dental tissue with the close apposition of the edges of the dental wound. This is the form of dental healing one might expect after the excision of a dental lesion in an area of the oral cavity where the pliability of the dental tissue is such that the dental wound may be drawn together and sutured.

When the edges of the dental wound are brought into contact and held in place by sutures, the blood clots, and in a matter of hours numerous leukocytes are mobilized to the area. Connective dental tissue cells in the immediate vicinity undergo transformation into fibroblast which in turn undergoes mitotic division, and the new fibroblast begins to migrate into and across the line of dental incision. In time, these cells, when examined under dental surgical microscopes, form in thin delicate collagen fibrils which intertwine and coalesce in a general direction parallel to the surface of the dental wound. At the same time, endothelial cells of the dental capillaries begin to proliferate, and small capillary buds grow out and across the dental wound. These buds, when examined under dental surgical microscopes, eventually form new capillaries which are filled with blood. A rich network of young dental capillaries and dental capillary loops are formed.

When there is a close apposition of the edges of the dental wound, as seen under dental surgical microscopes, the surface epithelium proliferates rapidly across the line of dental incision and reestablishes the integrity of the surface. The delicate connective tissue fibrils eventually coalesce into denser bundles and usually contract is that in time all that is left to indicate the dental biopsy area is a small linear scar which may be depressed below the dental surface. Because there is a defect which must be filled with the new dental tissue, this type of dental wound heals rapidly.

Secondary Healing

Healing by second intention, healing by granulation or healing of an open dental wound occurs when there is a loss of dental tissue and the edges of the dental wound cannot be approximated. Healing of this type is often spoken of as a process in which the dental wound “granulates in”, since the material which fills the defect during the healing process is called a granulation tissue. This type of dental wound is a result of dental biopsy of a lesion in an area of the oral cavity in which the dental tissue are not pliable and in which the dental edges cannot be approximated.

Indications

a.) Prolonged delay between Laceration and treatment

b.) See Laceration Repair

c.) Minor soft tissue amputations without bone loss

d.) Less than 1 cm square in size

e.) No significant volar pulp loss

f.) If unsure:

i.) Temporize with management below

ii.) Arrange follow-up and possible graft in 1-2 days

Management

a.) Cleansing

b.) Debridement

c.) Healing by secondary intention

d.) Dressing Changes

i.) Twice daily for 2 days after injury, then daily

ii.) Apply tube gauze and petroleum jelly

e.) Anticipatory Guidance

i.) Recovery in 2-3 weeks